Recliner chairs and lift chairs have been on the market for years, with the utility of recliners being primarily for use in living rooms and family rooms, while lift chairs are used by the handicapped, elderly, or disabled to assist them in moving from a reclined or sitting position to a standing position. While a substantial number of today's recliners are still manually operated, a growing number of recliners, and almost all lift chairs, utilize one or more actuators to move the footrest, back frame, and seat frame into various positions with respect to each other including reclining positions within a specified range, as well as to physically lift the chair while tipping it forward to aid the occupant to stand up. In one known chair type, independent movement of the footrest and backrest is accomplished through the use of separate actuators, while other chairs utilize a single interconnected actuator to cause the footrest and backrest to move together or simultaneously.
In addition to the usual television watching and other relaxing positions, a few known chairs can also be moved or pivoted into certain special positions. One of these is the so-called Trendelenburg position, wherein the occupant's legs are situated so that they are higher in relation to the ground than the heart. This position is useful particularly for those having certain circulatory, kidney, or other ailments, since in such position gravity assists the flow of blood from the legs back to the heart. Another special position is the so-called “zero gravity” or 90/90 position. To achieve such position, the chair is moved so that the head and torso are at a slight upward angle, the legs up to the knee are bent at a similar opposite upward angle, and the knees are bent so that the lower area of the legs is angled similarly to the torso. The zero-gravity position approximates the position or posture that astronauts assume when sleeping in a weightless environment. The primary benefit of such position is reduced pressure on the spine, which often relieves back pain at least to some extent.
One known lift and recline mechanisms developed by the assignee of the present invention that addresses some of the issues with respect to positioning the back frame relative to the seat frame is described in U.S. Pat. No. 9,016,788, which is incorporated herein by reference as if fully set forth. Other known lift and recline mechanisms use one or two actuators are also known from U.S. Pat. No. 8,308,228 and U.S. Patent Application Publication 2001/0035668
One specific issue that is not addressed by these known lift and recline mechanisms is that extra lift may be required for certain users, as well as that further positions that provide comfort to a user in the reclined position may be desirable, but are limited by the specific travel path of the lift and recline mechanism.